1) The context was whether a well designed mirror would have much more drag than no mirror at all. I argue that it doesn't have matter in the context of the cross sectional area of the car against the small area of the mirrors.
2) Aerodynamic drag is one of many factors in efficiency. Rolling resistance at those speeds is likely a bigger factor, but there are also mechanical systems that have inefficiencies that add up.
The important thing to remember is that drag increases with the cube of the velocity:
I think turbulence behind the mirror, which are like little ailerons :-), is what would make them drag,
You can even simulate such things quickly with fluid dynamic simulators on your computer in a few minutes these days... Technology :-).
With speed, you'd have to change the angle of the spoilers in front of the mirror to reduce turbulence behind it (a bit like in race cars). Or you can statically configure it for the worse case (like I suspect most cars do).
Cook said he was kidding about having new products to unveil. Not sure what that has to do with his iPad comment.
Ah, ok, I misunderstood then. Thanks.
I do think however he could also have meant it in a different way: self mockery. In order to point out how good the current models are, make a derogative remark about an older model.
Yes! Sorry. Scatterbrained as of late; things aren’t going well. It was half joking/half serious. They might well use a ‘standard’ charger if they made a car, but knowing Apple I wouldn’t put it past them to come up with something proprietary that could charge their batteries 10x faster or something.
Here's to really hoping that you are right.
If they can get it to where you get around 300 miles of range on a charge and it takes around 15 minutes to get back up to ~80% of your full range, I think that would definitely be more than acceptable and make EV's totally mainstream.
Maybe he got a lot of pushback from Tesla customers who also were Apple users. My neighbors are Tesla owners and wear an Apple Watch, own iPhone 6's and iMacs; they weren't too pleased when they heard Musk trashtalking Apple.
2) That was a stupid thing for him to say. Looks like he's human after all.
I think he's really saying "look how far the iPad has evolved, we've come so far we're embarrassed with our advanced capabilities in the latest version". Doesn't seem like he's embarrassed with the products, just that he's amazed. In context, I think he meant "amazed".
As you said, the delta in cross sectional area with/without mirrors is not the entire picture. This is not my area of expertise, however, looking at this as a cross sectional problem is too simplistic. Tesla's air suspension and aero wheels have both been shown to improve range, and neither alter the cross section of the vehicle.
I believe the issue on mirrors has more to do with turbulence and laminar flow, and this changes with varying speeds.
Quote:
Originally Posted by foggyhill
I think turbulence behind the mirror, which are like little ailerons :-), is what would make them drag,
You can even simulate such things quickly with fluid dynamic simulators on your computer in a few minutes these days... Technology :-).
With speed, you'd have to change the angle of the spoilers in front of the mirror to reduce turbulence behind it (a bit like in race cars). Or you can statically configure it for the worse case (like I suspect most cars do).
I think that you are missing the essential message that I am attempting to make.
At low speeds, even at 70 mph, the Tesla is only using about 14 hp to overcome drag. The rest of the hp output at 70 mph goes towards rolling resistance, drive train inefficiencies, cooling the motors/batteries, etc, which are collectively higher than the drag. Given that, the 2% drag penalty from these well designed mirrors is about 0.3 hp at 70 mph; quite low. It pays to improve aerodynamics certainly, but if your target is 70/80 mph cruise, all that additional effort, and cost, in aerodynamics improvements has little real benefit. It would likely improve top speed, a bit, and maybe that in itself is worth it from a marketing standpoint.
If you are a production automaker with a design budget, pursuing the last bit of aerodynamic efficiency is mostly a wasted effort. Better to create a balanced design that improves all aspects of the car, especially related to the rolling resistance/handling tradeoff of high performance tires.
There are indeed a number of apps available for the Mac for Computational Fluid Dynamics, and some 2d versions (maybe even some 3d versions) for the iPhone and iPad. Note that a properly calibrated wind tunnel will give better results than uncalibrated CFD models, and because wind tunnel time is very expensive, most use Wind tunnel data to validate their CFD models when that is an option.
It would make sense for Tesla to create a special "tuned" version as a limited edition with many small improvements, but again, it would only likely improve the top speed a small amount.
The truth is that any battery improvements will be far more effective for Tesla efficiency than fine tuning aerodynamics at a high level of effort; that would give a much better range improvement over squeezing out a little more aerodynamic efficiency.
I should state that I agree with removing the mirrors for a vehicle intended to drive at high speeds on a track make sense, it allowed by the racing body; it just doesn't matter for a vehicle that spends its life on regulated roadways.
Elon has impeccable timing. Doesn't he know it's raise and bonus time of year at Apple? I know of at least one person who was thinking about spending their bonus on a new Tesla, but not anymore.
Looks like your mouth is costing you more than just engineers Elon.
I think he's really saying "look how far the iPad has evolved, we've come so far we're embarrassed with our advanced capabilities in the latest version". Doesn't seem like he's embarrassed with the products, just that he's amazed. In context, I think he meant "amazed".
That he’s embarrassed with the first iPad in the context of modern ones crossed my mind, but if that was his intent, it could have been worded more plainly. It’s also a lame sentiment, since of course past achievements are going to look bad in the face of modern ones.
It’s like berating the engineers at the start of WWI for not just immediately thinking that the tank would replace cavalry.
I think he's really saying "look how far the iPad has evolved, we've come so far we're embarrassed with our advanced capabilities in the latest version". Doesn't seem like he's embarrassed with the products, just that he's amazed. In context, I think he meant "amazed".
I'm not buying that argument. If that's the case, it's still an extremely poor choice of words. In comparison to my iPhone 6S-series, all other iPhones are comparatively embarrassing, if we are to use that word in that way. Because the original iPad fell well below the average length of time for an iDevice iOS upgradability, likely because of the RAM, I'd say his usage is likely intended to indicate shame.
If they can get it to where you get around 300 miles of range on a charge and it takes around 15 minutes to get back up to ~80% of your full range, I think that would definitely be more than acceptable and make EV's totally mainstream.
I think that's highly unrealistic. While I fully expect battery technology to make significant jumps in capacity over the next few years, the same can't be said for chargers. Teslas Superchargers output 120kw. And even then it takes 40 minutes to hit 80%. To do the same in 15 minutes would require roughly 320kw. That is a ridiculously large amount of power to pass through a cable/plug to your vehicle safely.
For comparison, the typical electrical service to your house (detached average size home, not condo) is probably 24kw (240v X 100A). A Tesla Supercharger is already 5 time that amount.
I think the range of electric cas will go up signifcantly as battery technology improves. But chargers are limited by physics and can't really improve. It takes so many watts to move a car a certain distance regardless of the size of your battery. You want to drive further - you need to charge longer.
I think that you are missing the essential message that I am attempting to make.
At low speeds, even at 70 mph, the Tesla is only using about 14 hp to overcome drag. The rest of the hp output at 70 mph goes towards rolling resistance, drive train inefficiencies, cooling the motors/batteries, etc, which are collectively higher than the drag. Given that, the 2% drag penalty from these well designed mirrors is about 0.3 hp at 70 mph; quite low. It pays to improve aerodynamics certainly, but if your target is 70/80 mph cruise, all that additional effort, and cost, in aerodynamics improvements has little real benefit. It would likely improve top speed, a bit, and maybe that in itself is worth it from a marketing standpoint.
If you are a production automaker with a design budget, pursuing the last bit of aerodynamic efficiency is mostly a wasted effort. Better to create a balanced design that improves all aspects of the car, especially related to the rolling resistance/handling tradeoff of high performance tires.
There are indeed a number of apps available for the Mac for Computational Fluid Dynamics, and some 2d versions (maybe even some 3d versions) for the iPhone and iPad. Note that a properly calibrated wind tunnel will give better results than uncalibrated CFD models, and because wind tunnel time is very expensive, most use Wind tunnel data to validate their CFD models when that is an option.
It would make sense for Tesla to create a special "tuned" version as a limited edition with many small improvements, but again, it would only likely improve the top speed a small amount.
The truth is that any battery improvements will be far more effective for Tesla efficiency than fine tuning aerodynamics at a high level of effort; that would give a much better range improvement over squeezing out a little more aerodynamic efficiency.
I should state that I agree with removing the mirrors for a vehicle intended to drive at high speeds on a track make sense, it allowed by the racing body; it just doesn't matter for a vehicle that spends its life on regulated roadways.
I don't know where your numbers come from, but certainly there is a diminishing returns issue at play - however the removal of the mirrors will come at little cost, and most likely be a net gain ($) for the mfgs. Especially in light of little to no additional instrumentation required as the autonomous vehicle effort will be the impetus for the added sensors/cameras. With the way things appear to be headed, there is little doubt in my mind that the mirrors will soon be a useless appendage, and will give some improvement in range.
I do think however he could also have meant it in a different way: self mockery. In order to point out how good the current models are, make a derogative remark about an older model.
I'm not buying that argument. If that's the case, it's still an extremely poor choice of words. In comparison to my iPhone 6S-series, all other iPhones are comparatively embarrassing, if we are to use that word in that way. Because the original iPad fell well below the average length of time for an iDevice iOS upgradability, likely because of the RAM, I'd say his usage is likely intended to indicate shame.
It's entirely possible that Cook does feel this way. The first gen iPad did have a pretty short shelf life compared to the one that replaced it.
That's not entirely accurate. Talking about side mirrors, if you adjust them out, you can eliminate the blind spot. Most people were taught to adjust them so that they see the rear of their car in them, but that's exactly what creates the blind spot. I'm proud to say that I figured this out on my own after several decades, and I confirmed it when I got home by googling /adjust mirrors to eliminate blind spot/.
Even adjusting the mirrors you still get blindspots. I have my mirrors adjusted so I see the next lane but this is still not enough. It's fine if the vehicle is behind you but if it's beside you and you glance at your rear view mirror you'll never see them, worse if the other vehicle is a motorcyclist.
As a motorcyclist I by nature turn my head to remove the blindspots.
I once almost became a cropper when I pulled out to pass a car driven by an old man. I was looking at this car as I passed him because it was a beautiful example of an old Impala. I then started to get this weird feeling and that's when I realised he was trying to pull into the same lane that I was already in. Not once did that old guy's head move and I was forced into the other lane which had oncoming traffic. I was able to get out of the situation because the oncoming cars could see what was going on and slowed down and I dropped into 3rd gear to ring the crap out of the car and get passed him. All the old fart had to do was turn his head and he would have seen me.
That's why I feel safer on a motorcycle than in a car. On a bike you can get out of things much easier than in a car.
Can you point me to any posts you made in 2010 about how embarrassing it was for Apple to release the original iPad?
Well I wasn't posting here back then. But there's a difference between the iPad as an idea and the first iPad that was released. Hence why you probably won't find a lot of people still using iPad 1 but a whole lot of people (many I know) using iPad 2. One could probably say the same thing about the first MacBook Air.
Did you also suggest Steve Jobs to shut the fuçk up when he was started NeXT and bought Pixar because I'm pretty sure he had things to say about Apple, MS, IBM, and many others, or was that different.
Just like your hero, crude. You clearly have no context from a financial pic. Musk is a fat little pug, suckling on the government handout teat. My comments stand about his comments. To my recollection Jobs wasn't running around disparaging profitable companies. You really need some context. Maybe when you grow out of your teenage years you might get some perspective on the real world . Perhaps you'd like to provide some valid Jobs quotes to back up your allegations? Oh- you can't do that? What a surprise.
I don't know where your numbers come from, but certainly there is a diminishing returns issue at play - however the removal of the mirrors will come at little cost, and most likely be a net gain ($) for the mfgs. Especially in light of little to no additional instrumentation required as the autonomous vehicle effort will be the impetus for the added sensors/cameras. With the way things appear to be headed, there is little doubt in my mind that the mirrors will soon be a useless appendage, and will give some improvement in range.
Mirrors will be required by regulation for quite awhile.
My numbers are documented in my various posts, most of which are linked as well. I did use 2% drag as a figure for a well designed mirror on a passenger car, and I based that on a paper that was linked by techlover; that's 2% of the cars total drag, You don't seem to want to delve into this in any detail, just offer an opinion. That's fine, but why people are so focused on the mirror as some sort of major inefficiency is beyond me, the numbers belie that. So, I'm out of here.
You will likely be correct about mirrors disappearing when autonomous vehicles arrive in a reasonable numbers, but I would be surprised it there will be actual "autonomy" in all driving environments for another decade; so expect mirrors to be required for quite some time.
Can you point me to any posts you made in 2010 about how embarrassing it was for Apple to release the original iPad?
Well I wasn't posting here back then. But there's a difference between the iPad as an idea and the first iPad that was released. Hence why you probably won't find a lot of people still using iPad 1 but a whole lot of people (many I know) using iPad 2. One could probably say the same thing about the first MacBook Air.
Oh quit it. You didn't even bother to read the link I sent you, did you? Couldn't handle the cognitive dissonance?
You didn't like the iPad 1. Lots of people did (it was, after all the fastest selling Apple product of all time). Cook didn't like the iPad 1. Jobs did. ("One million iPads in 28 days—that's less than half of the 74 days it took to achieve this milestone with iPhone. Demand continues to exceed supply and we're working hard to get this magical product into the hands of even more customers.".
I know which collection of views on aesthetics I'd take any day. There's not much more to your pointless trash-talking of the original iPad.
It's entirely possible that Cook does feel this way. The first gen iPad did have a pretty short shelf life compared to the one that replaced it.
What does that mean? I still have an iPad 1st gen. 64GB around (likely should put it up on eBay though) Why exactly did you think the iPad 1st gen had " a pretty short shelf life compared to the one that replaced it." Our 1st gen was being used regularly up until about a year or so ago when we went to iCloud drive (which kind of isolated it) But I have no qualms about it's useful lifetime, it owes us nothing. Actually I had a pretty hard time finding it when I bought it (about a month after it was released) the iPad 1's sales were VERY supply constrained during it's first few months.
AFAICR the iPad first and second gen. both had a year, which is about all most portable devices have. Innovation, particularly at Apple, has a rapid timeline. (Actually... As I recall,l there WAS a short cycle between the 3rd and 4th gen (only 6 months) when they switched to fall releases.)
Comments
1) The context was whether a well designed mirror would have much more drag than no mirror at all. I argue that it doesn't have matter in the context of the cross sectional area of the car against the small area of the mirrors.
2) Aerodynamic drag is one of many factors in efficiency. Rolling resistance at those speeds is likely a bigger factor, but there are also mechanical systems that have inefficiencies that add up.
The important thing to remember is that drag increases with the cube of the velocity:
The equation for air drag (via http://en.wikipedia.org/wiki/Dra... is
P = .5 * p * v^3 * A * Cd
I think turbulence behind the mirror, which are like little ailerons :-), is what would make them drag,
You can even simulate such things quickly with fluid dynamic simulators on your computer in a few minutes these days... Technology :-).
With speed, you'd have to change the angle of the spoilers in front of the mirror to reduce turbulence behind it (a bit like in race cars). Or you can statically configure it for the worse case (like I suspect most cars do).
Cook said he was kidding about having new products to unveil. Not sure what that has to do with his iPad comment.
Ah, ok, I misunderstood then. Thanks.
I do think however he could also have meant it in a different way: self mockery. In order to point out how good the current models are, make a derogative remark about an older model.
Yes! Sorry. Scatterbrained as of late; things aren’t going well. It was half joking/half serious. They might well use a ‘standard’ charger if they made a car, but knowing Apple I wouldn’t put it past them to come up with something proprietary that could charge their batteries 10x faster or something.
Here's to really hoping that you are right.
If they can get it to where you get around 300 miles of range on a charge and it takes around 15 minutes to get back up to ~80% of your full range, I think that would definitely be more than acceptable and make EV's totally mainstream.
I think he's really saying "look how far the iPad has evolved, we've come so far we're embarrassed with our advanced capabilities in the latest version". Doesn't seem like he's embarrassed with the products, just that he's amazed. In context, I think he meant "amazed".
As you said, the delta in cross sectional area with/without mirrors is not the entire picture. This is not my area of expertise, however, looking at this as a cross sectional problem is too simplistic. Tesla's air suspension and aero wheels have both been shown to improve range, and neither alter the cross section of the vehicle.
I believe the issue on mirrors has more to do with turbulence and laminar flow, and this changes with varying speeds.
I think turbulence behind the mirror, which are like little ailerons :-), is what would make them drag,
You can even simulate such things quickly with fluid dynamic simulators on your computer in a few minutes these days... Technology :-).
With speed, you'd have to change the angle of the spoilers in front of the mirror to reduce turbulence behind it (a bit like in race cars). Or you can statically configure it for the worse case (like I suspect most cars do).
I think that you are missing the essential message that I am attempting to make.
At low speeds, even at 70 mph, the Tesla is only using about 14 hp to overcome drag. The rest of the hp output at 70 mph goes towards rolling resistance, drive train inefficiencies, cooling the motors/batteries, etc, which are collectively higher than the drag. Given that, the 2% drag penalty from these well designed mirrors is about 0.3 hp at 70 mph; quite low. It pays to improve aerodynamics certainly, but if your target is 70/80 mph cruise, all that additional effort, and cost, in aerodynamics improvements has little real benefit. It would likely improve top speed, a bit, and maybe that in itself is worth it from a marketing standpoint.
If you are a production automaker with a design budget, pursuing the last bit of aerodynamic efficiency is mostly a wasted effort. Better to create a balanced design that improves all aspects of the car, especially related to the rolling resistance/handling tradeoff of high performance tires.
There are indeed a number of apps available for the Mac for Computational Fluid Dynamics, and some 2d versions (maybe even some 3d versions) for the iPhone and iPad. Note that a properly calibrated wind tunnel will give better results than uncalibrated CFD models, and because wind tunnel time is very expensive, most use Wind tunnel data to validate their CFD models when that is an option.
It would make sense for Tesla to create a special "tuned" version as a limited edition with many small improvements, but again, it would only likely improve the top speed a small amount.
The truth is that any battery improvements will be far more effective for Tesla efficiency than fine tuning aerodynamics at a high level of effort; that would give a much better range improvement over squeezing out a little more aerodynamic efficiency.
I should state that I agree with removing the mirrors for a vehicle intended to drive at high speeds on a track make sense, it allowed by the racing body; it just doesn't matter for a vehicle that spends its life on regulated roadways.
Elon has impeccable timing. Doesn't he know it's raise and bonus time of year at Apple? I know of at least one person who was thinking about spending their bonus on a new Tesla, but not anymore.
Looks like your mouth is costing you more than just engineers Elon.
That he’s embarrassed with the first iPad in the context of modern ones crossed my mind, but if that was his intent, it could have been worded more plainly. It’s also a lame sentiment, since of course past achievements are going to look bad in the face of modern ones.
It’s like berating the engineers at the start of WWI for not just immediately thinking that the tank would replace cavalry.
I'm not buying that argument. If that's the case, it's still an extremely poor choice of words. In comparison to my iPhone 6S-series, all other iPhones are comparatively embarrassing, if we are to use that word in that way. Because the original iPad fell well below the average length of time for an iDevice iOS upgradability, likely because of the RAM, I'd say his usage is likely intended to indicate shame.
I think that's highly unrealistic. While I fully expect battery technology to make significant jumps in capacity over the next few years, the same can't be said for chargers. Teslas Superchargers output 120kw. And even then it takes 40 minutes to hit 80%. To do the same in 15 minutes would require roughly 320kw. That is a ridiculously large amount of power to pass through a cable/plug to your vehicle safely.
For comparison, the typical electrical service to your house (detached average size home, not condo) is probably 24kw (240v X 100A). A Tesla Supercharger is already 5 time that amount.
I think the range of electric cas will go up signifcantly as battery technology improves. But chargers are limited by physics and can't really improve. It takes so many watts to move a car a certain distance regardless of the size of your battery. You want to drive further - you need to charge longer.
I'm sure that's what he meant and he's right.
Can you point me to any posts you made in 2010 about how embarrassing it was for Apple to release the original iPad?
It's entirely possible that Cook does feel this way. The first gen iPad did have a pretty short shelf life compared to the one that replaced it.
That's not entirely accurate. Talking about side mirrors, if you adjust them out, you can eliminate the blind spot. Most people were taught to adjust them so that they see the rear of their car in them, but that's exactly what creates the blind spot. I'm proud to say that I figured this out on my own after several decades, and I confirmed it when I got home by googling /adjust mirrors to eliminate blind spot/.
Even adjusting the mirrors you still get blindspots. I have my mirrors adjusted so I see the next lane but this is still not enough. It's fine if the vehicle is behind you but if it's beside you and you glance at your rear view mirror you'll never see them, worse if the other vehicle is a motorcyclist.
As a motorcyclist I by nature turn my head to remove the blindspots.
I once almost became a cropper when I pulled out to pass a car driven by an old man. I was looking at this car as I passed him because it was a beautiful example of an old Impala. I then started to get this weird feeling and that's when I realised he was trying to pull into the same lane that I was already in. Not once did that old guy's head move and I was forced into the other lane which had oncoming traffic. I was able to get out of the situation because the oncoming cars could see what was going on and slowed down and I dropped into 3rd gear to ring the crap out of the car and get passed him. All the old fart had to do was turn his head and he would have seen me.
That's why I feel safer on a motorcycle than in a car. On a bike you can get out of things much easier than in a car.
Well I wasn't posting here back then. But there's a difference between the iPad as an idea and the first iPad that was released. Hence why you probably won't find a lot of people still using iPad 1 but a whole lot of people (many I know) using iPad 2. One could probably say the same thing about the first MacBook Air.
I don't know where your numbers come from, but certainly there is a diminishing returns issue at play - however the removal of the mirrors will come at little cost, and most likely be a net gain ($) for the mfgs. Especially in light of little to no additional instrumentation required as the autonomous vehicle effort will be the impetus for the added sensors/cameras. With the way things appear to be headed, there is little doubt in my mind that the mirrors will soon be a useless appendage, and will give some improvement in range.
Mirrors will be required by regulation for quite awhile.
My numbers are documented in my various posts, most of which are linked as well. I did use 2% drag as a figure for a well designed mirror on a passenger car, and I based that on a paper that was linked by techlover; that's 2% of the cars total drag, You don't seem to want to delve into this in any detail, just offer an opinion. That's fine, but why people are so focused on the mirror as some sort of major inefficiency is beyond me, the numbers belie that. So, I'm out of here.
You will likely be correct about mirrors disappearing when autonomous vehicles arrive in a reasonable numbers, but I would be surprised it there will be actual "autonomy" in all driving environments for another decade; so expect mirrors to be required for quite some time.
Oh quit it. You didn't even bother to read the link I sent you, did you? Couldn't handle the cognitive dissonance?
You didn't like the iPad 1. Lots of people did (it was, after all the fastest selling Apple product of all time). Cook didn't like the iPad 1. Jobs did. ("One million iPads in 28 days—that's less than half of the 74 days it took to achieve this milestone with iPhone. Demand continues to exceed supply and we're working hard to get this magical product into the hands of even more customers.".
I know which collection of views on aesthetics I'd take any day. There's not much more to your pointless trash-talking of the original iPad.
It's entirely possible that Cook does feel this way. The first gen iPad did have a pretty short shelf life compared to the one that replaced it.
What does that mean? I still have an iPad 1st gen. 64GB around (likely should put it up on eBay though) Why exactly did you think the iPad 1st gen had " a pretty short shelf life compared to the one that replaced it." Our 1st gen was being used regularly up until about a year or so ago when we went to iCloud drive (which kind of isolated it) But I have no qualms about it's useful lifetime, it owes us nothing. Actually I had a pretty hard time finding it when I bought it (about a month after it was released) the iPad 1's sales were VERY supply constrained during it's first few months.
AFAICR the iPad first and second gen. both had a year, which is about all most portable devices have. Innovation, particularly at Apple, has a rapid timeline. (Actually... As I recall,l there WAS a short cycle between the 3rd and 4th gen (only 6 months) when they switched to fall releases.)